Abstract: A low-voltage power amplifier system achieves high efficiency with a low power supply and a low input voltage. The low-voltage power amplifier system includes an enable input for switching the system between an ON state and an OFF state. The low-voltage power amplifier system can directly amplify the input signal and can achieve a frequency multiplication by an even factor. The low-voltage power amplifier system includes a biasing capacitor, a biasing resistor, a npn or pnp transistor, an output or resonant inductor, an output or resonant capacitor, and an optional stability resistor.

Abstract: A method for generating quasi-sinusoidal signals includes illuminating an object capable of reflecting light, focusing a portion of the reflected light on a multi-element detector to form an image, and matching the image size to the size of the detector elements. A first weighted sum of signals generated by a first set of elements produces an in-phase signal, and a second weighted sum of signals generated by a second set of elements produces a quadrature signal. Weights are signed quantities selected to exhibit a band-pass behavior in the spatial frequency domain, thereby attenuating noise generated by, for example, non-uniform surface reflectance and non-uniform illumination.

Abstract: The present invention provides a touch pad which can detect a simply stylus using a change capacitance. The touch pad is made flexible, so that the stylus pressure compresses an insulating layer between a conductive reference layer and matrix of conductive traces. The compression causes a change in capacitance due to either the two capacitive conductive surfaces being closer to each other, or a variation of the dielectric value of the insulating layer due to the replacement of air in air gaps by the material of the insulating layer.

Abstract: An improved flexible substrate for a touchpad, with the flexible substrate having conductive ink for forming a sensor array. A printed circuit board is also used, but only for the components which need to connect to the array, and not the array, thus giving a smaller printed circuit board. The printed circuit board can have the components compactly mounted on it taking advantage of the close spacing available in PC board technology. The PC board itself has wider spacing on its contacts at its outer edges, allowing it to be attached by conductive glue to the flexible substrate.

Abstract: A touchpad which simulates an active stylus by providing pulses to the entire active plane (making it an active plane), instead of the stylus. This allows a simple, non-active stylus to compress the touchpad to bring the X, Y traces closer to the active plane at the point to be detected. The phase of the pulses applied to the active ground could be chosen to make a stylus look like a finger, or to differentiate it. The pulses are applied synchronously with the standard triangular waveform applied to traces in the trace matrix. The other traces not being sampled at a particular time are truly grounded, and thus are separated from the active plane.

Abstract: Method and apparatus for sensing the simultaneous proximity of one or more fingers or other appropriate objects to a capacitive touch sensor. A modulator/demodulator pair drive and sense either a single trace or a pair of traces. In a dual trace embodiment, differentially sensed signals are then peak detected converted from voltage to current. The output signal is then calibrated to adjust for trace variations, followed by appropriate gain and level shifting, and analog-to-digital conversion for use as the input to a microcontroller.

Abstract: The present invention relates to a trackball/actuator assembly for a portable computer that includes one or more free pivot-arm key plates disposed around a trackball module. According to one embodiment of the present invention, it includes a housing having a top surface and sidewalls extending downward from opposite ends of the top surface, a first keyplate protruding from the top surface between the sidewalls, a second keyplate protruding from the top surface between the sidewalls, and a trackball disposed between the keyplates. First and second pivot joints formed integral to the first and second sidewalls, respectively, form a first horizontal axis between the sidewalls that is offset from the first keyplate. The first keyplate is rotatably coupled to first and second pivot joints so that it pivots freely about the first horizontal axis.

Abstract: A joystick having an electromagnetic element coupled to a movable stick, with at least a pair of orthogonal coils on an underlying substrate. Alternately, the coils and electromagnetic elements can be reversed. The movement of the stick is detected by the amount of overlap of the electromagnetic element and the coils in each direction. The quality factor of the coil changes as more or less of the coil is overlapped, which can be measured by an electric circuit to determine the direction of movement and the amount of movement of the joystick. The electromagnetic element could be, for instance, a conductive steel plate, or a piece of another metal or of another conductive material, or ferrite particles. The coil could be wound (preferably on air only or, if needed to reach a higher value of inductance, on a magnetic core, provided this is small enough to not hide the effect of the mobile electromagnetic element).

Abstract: An optical detection system particularly suited to us as a pointing device uses a photodetector array capable of generating a quasi-sinusoidal signal in response to illumination with an image of appropriate size. The detection system can use either coherent or non-coherent light, and existing textures in standard materials such as paper or printed patterns.

Abstract: The present invention provides an improved image scanner which has a hollow platen, with a motor mounted inside the platen. A drive mechanism is coupled between the motor and the inside surface of the platen to rotate the platen. Preferably, a circuit board containing circuitry for at least controlling the motor is also mounted inside the platen.

Abstract: A method and apparatus for establishing a standardized communications protocol for wireless communications between a host and one or more peripheral devices such as joysticks, mice, gamepads, remote controllers or other devices including establishing a standard message format for messages communicated between a host and the peripheral devices, establishing a plurality of unique data types for associated peripheral devices, and prioritizing communications between the host and such peripherals to permit rapid and effective communication therebetween.

Abstract: A method and apparatus for attaching a pointing device, such as a mouse, a trackball, a joystick, or the like to an edge of a keyboard or any protruding edge. The apparatus includes a body, a clamping edge adjustably attached to the body, and a movable slide movably attached to the body. The movable slide has a slide face facing the clamping edge such that a gap is formed between the slide face and the clamping edge. One or more springs bias the movable slide against the clamping edge to grip the protruding edge to which the pointing device is attached. The clamping edge can be attached to the body at different positions to accommodate protruding edges of different thickness.